Method of preparing glyphosate herbicide formulations

ABSTRACT

This invention relates to a novel aqueous agriculturally acceptable formulation, a process used to prepare it and a pesticidal method of using it in application to plants or weeds to kill or control plants or weeds. The formulation comprises an effective amount of N-phosphonomethylglycine or an agriculturally acceptable salt of N-phosphonomethylglycine and an effective amount of at least one C 5  to C 16  or preferably a C 8  to C 12  agriculturally acceptable fatty acid itself or in the form of an agriculturally acceptable water soluble salt or mixtures thereof. Other ingredients are optional, including surfactant(s), antifoam(s) and antimicrobial(s) or other ingredients such as pesticides including herbicides, insecticides and fungicides.

This is a continuation of application Ser. No. 08/790,400, filed Jan.29, 1997 now U.S. Pat. No. 5,994,269 which is a continuation applicationof Ser. No. 08/464,028 filed Jun. 5, 1995, now abandoned; which is adivisional application of Ser. No. 07/638,590, filed Jan. 8, 1991, nowabandoned.

FIELD OF THE INVENTION

This invention relates to a novel aqueous agriculturally acceptableherbicidal formulation, a process used to prepare it and a herbicidalmethod of using it in applying it to weeds or plants to kill and controlweeds or plants.

The formulation, preferably a herbicidally efficacious formulation,comprises an effective amount of an agriculturally acceptable salt ofN-phosphonomethylglycine and a herbicidally effective amount of at leastone agriculturally acceptable fatty acid or a salt thereof or a mixtureof fatty acids and a salt(s) thereof or a mixture of salts of a fattyacid(s) giving in an aqueous solution to be applied to plants or adesired locus a pH in a desired range. Other ingredients are optional,including surfactant(s), antifoam(s), antimicrobial(s) or one or moreadditional pesticides including herbicides, insecticides and fungicides.As used herein, the term “agriculturally acceptable” includesresidential and industrial uses.

DESCRIPTION OF THE PRIOR ART

Glyphosate (N-phosphonomethylglycine) well-known as an effectiveherbicide is an organic acid, and is relatively insoluble in water.Therefore, glyphosate is normally formulated and applied as awater-soluble salt, especially as the isopropylamine salt (IPA salt).

Various formulations of glyphosate are disclosed in U.S. Pat. Nos.4,405,531 issued to John E. Franz on Sep. 20, 1983; 3,799,580 issued toJohn E. Franz on Mar. 26, 1974; and 4,840,659 issued to John E. Franz onJun. 20, 1989. These patents are incorporated herein by reference intheir entirety. Roundups herbicide an aqueous concentrate comprising theIPA salt of glyphosate is sold by Monsanto Company as an aqueousconcentrate formulation which is normally diluted in water prior toapplication.

Sharpshooter(TM) Herbicide Concentrate from Safer Inc. is said tocontain fatty acid(s) as active ingredients such as those having 8 to 12carbon atoms and mixtures thereof. It is believed used as a vegetationsuppression agent.

SharpShooter(TM) is non-selective, and shows the result of its contactwith weeds and unwanted vegetation in the form of necrosis, leaf burn,desiccation, wilting and the like. Typical fatty acids known to producesuch symptoms are pelargonic and n-capric acid.

Pelargonic acid referred to also as nonanoic acid, nonylic acid andnonoic acid has the empirical formula C₉H₁₈O₂.

n-Capric acid known also as n-decanoic acid, has the empirical formulaC₁₀H₂₀O₂.

PCT/US88/03582 (WO89/03178) of Safer, Inc. discloses a herbicidalcomposition and method for non-selectively controlling and retarding thegrowth rate and, if desired, causing extensive mortality of unwantedvegetation. The compositions consist essentially of one or moresubstances selected from the group consisting of aliphatic acids ortheir herbicidally active salts, disclosed preferably as octanoic acid,nonanoic acid, decanoic acid, n-decanoic acid, or dodecanoic acid, andan ammonium compound, preferably ammonium nitrate, sulfate or sulfanate.The composition is said to cause a plant mortality significantly inexcess of the expected additive mortalities of the individualcomponents.

U.S. Pat. No. 4,975,110 issued to George S. Puritch et al discloses anenvironmentally compatible herbicidal composition, consistingessentially of a herbicidally effective amount of a saturated linearmonocarboxylic fatty acid selected from the group consisting of theacids caprylic, pelargonic, capric, undecanoic, lauric and mixturesthereof; and a surfactant component.

U.S. Pat. No. 3,870,503 issued to Louis G. Nickell on Mar. 11, 1975discloses that sucrose yield of sugar-cane is increased by treatingsugarcane a few weeks prior to harvest with a sugar cane ripening agentselected from the group consisting of n-valeric (pentanoic) acid andalkali metal salts or ethyl esters of an aliphatic monoacid having fromone to five carbon atoms.

U.S. Pat. No. 4,134,754 issued to Otto L. Hoffmann on Jan. 16, 1979discloses that the activity of barban is enhanced and variation ofselectivity with climatic conditions is alleviated by applying to wildoats an effective amount of a composition comprising one part by weightcarbon and at least four parts by weight of a polyunsaturated fatty acidexemplified by linolenic acid. The composition is preferably eitherdispersed in water with the aid of an emulsifier or dissolved in amixture of water and a volatile organic solvent such as acetone.

U.S. Pat. No. 4,436,547 issued to Michael J. Sampson on Mar. 13, 1984discloses that the effect of fungicides, herbicides, insecticides,nematocides and plant-growth regulators, is improved byco-administration of them with one or more of the following additives:carbohydrates, organic acids (particularly fatty acids and acids of theKrebs tricarboxylic acid cycle), vitamins and co-enzymes, purine andpyrimidine nucleosides and nucleotides, naturally occurring fats andoils, certain amino acids and (but not where the agricultural chemicalis itself a plant-growth regulator) plant-growth regulators. Theinvention is said to provide compositions containing one or more of thesaid agricultural chemicals and one or more of the said additives andmethods of improving the harvest of a given crop by applying to it oneor more of the said agricultural chemicals and one or more of theadditives, either simultaneously or within up to about ten days of oneanother.

U.S. Pat. No. 4,626,274 issued to Heinz Hausmann on Dec. 2, 1986discloses that a known herbicide such as a urea, carboxylic acid ester,aminoacid, benzoic derivative, benzonitrile, phenol derivative, diphenylether, triazinone, triazinedione, heterocycle, dipyridil derivative orbenzosulphonamide, is rendered more effective by being combined with asynthetic spreading agent such as a silicone oil, etc.

U.S. Pat. No. 4,966,728 issued to James L. Hazen, on Oct. 30, 1990discloses herbicide adjuvants which are said to enhance theeffectiveness of a broad spectrum of postemergent herbicides. Theseadjuvants preferably contain a low foaming nonionic surfactant, ananionic surfactant, a lower alkanol ester of a fatty acid, and ahydrocarbon oil component.

U.S. Pat. No. 4,902,334 issued to Azuma et al on Feb. 20, 1990 disclosesa plant metabolism regulating agent comprising as an active ingredientan alpha, beta or beta, gamma-unsaturated carboxylic acid or itsderivative. This concept is said to be useful for controlling themetabolism of a plant, facilitating the growth of a beneficial plantsuch as cereals by inhibiting the growth of undesirable plants oreradicating them, regulating the growth of a plant and dwarfing a plant.

U.S. Pat. No. 4,904,645 issued to George S. Puritch et al on Feb. 27,1990 discloses a combination of pyrethrum and fatty acid salt materialwhich is said to provide a stable; commercially useful andenvironmentally safe pesticidal formulation. The specific compositioncomprises an aqueous solution having a pH within the range of 7.5 to8.8; an aqueous solution comprising about 50% by weight ofmonocarboxylic acids and their alkali metal salts, where the acidmixture is at least 70% oleic acid and 6% linoleic acid; a pyrethrumextract; a solvent for the pyrethrum, which is preferably a 2-6 carbonalcohol; a trace amount of an antioxidant. The composition is said to beeffective against insects of at least the orders Homoptera, Coleoptera,Dermaptera, Hemiptera, and Lepidoptera, and against crustacea of theorder Isopoda.

OBJECTS OF THE INVENTION

An objective of this invention is to provide an aqueous concentrate orready to apply formulation comprising glyphosate or a water soluble saltof glyphosate and a fatty acid or a salt thereof or a mixture of fattyacids and salt thereof or a mixture of salts of the fatty acid(s) suchthat the early burndown symptoms on plants of the fatty acid and/or itssalt or mixtures thereof are seen and the long term herbicidal controlachieved by the use of the glyphosate is maintained and not sacrificed,eliminated or reduced by the contact action of the fatty acid or itswater soluble salt. Enhanced shelf-stability is provided when theapplication pH is in the preferred range.

Without being bound by theory, it is believed that the fatty acid is theresponsible moiety for providing the early contact visible symptoms onplants treated with a fatty acid salt contained in a formulation of thisinvention.

BRIEF DESCRIPTION OF THE INVENTION

The foregoing objects are provided in an agriculturally acceptableherbicidal composition comprising herbicidally effective amounts of eachof:

a) N-phosphonomethylglycine (glyphosate) or an agriculturally acceptablewater soluble salt of N-phosphonomethylglycine or a compound whichmetabolizes thereto and

b) a fatty acid such as a C₅ to C₁₆ or preferably a C₈ to C₁₂ saturatedor unsaturated, straight or branched chain fatty acid or anagriculturally acceptable salt(s) thereof or a mixture of fatty acidsand salt(s) thereof or a mixture of salts of a fatty acid(s) recognizingthat such fatty acids may themselves be mixtures.

A preferred composition is wherein the ratio of a) to b) is in the rangefrom about 1:10 to about 10:1 by weight and more preferably wherein theratio of a) to b) is in the range from about 1:5 to about 5:1 and mostpreferably in the range from about 1:3 to about 3:1.

Especially preferred are the mono-isopropylamine and thetrimethylsulfonium salts of N-phosphonomethylglycine.

Especially preferred are the potassium salts of capric fatty acid andpelargonic fatty acid and mixtures thereof. Potassium nonanoate andpotassium decanoate may be enployed.

Also disclosed is a method of killing or controlling plants where aherbicidally effective amount of the above described herbicidalcomposition is applied to said plants to kill or control said plants andwherein the early burndown effect of application of the fatty acid or asalt thereof can be readily seen leaving intact the longer term controlopportunity which is provided by simultaneous application of glyphosateor of the glyphosate moiety in the form of a water soluble salt ofglyphosate or a compound which metabolizes to glyphosate.

Also disclosed is a process for preparing herbicidal compositions ofthis invention wherein a base such as those providing hydroxide in waterpreferably an amine or alkali metal or alkaline earth metal hydroxidemost preferably potassium hydroxide is employed to control the desiredfinal adjusted pH in the range from about 6.4 to about 7.25 andpreferably in the range from about 6.8 to about 7.0 to provide animproved storage stable formulation, which is ready to use or ready todilute.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to an agriculturally acceptableherbicidal, shelf-stable ready to use or shelf-stable aqueousconcentrate formulation of N-phosphonomethylglycine or a water solublesalt of N-phosphonomethylglycine or salts or mixtures thereof, with oneor more C₅ to C₁₆ or preferably C₈ to C₁₂ saturated or unsaturated,straight or branched chained fatty acid itself or in the form of a salt,salts or various mixtures thereof.

Various optional ingredients may also be employed if desired althoughnot required. Greater or lesser amounts of those optional additimentsmay be employed as desired.

When the application pH of the formulation of the present invention isin the range from about 6.4 to about 7.25, and more preferably in therange from about 6.8 to about 7.0, the formulations of this inventionshow increased shelf-stability in that they do not experience separationsuch as salting out or settling out of one or more ingredients whenstored for prolonged periods of time at normal room temperatures or whenundergoing accelerated aging studies done at 50° C. or 60° C. or atfreezing temperatures.

As used herein, the phrase “early burndown symptoms” means visible plantsymptoms characteristic of the contact action of a fatty acid or a saltthereof upon the leaf of a plant when applied in an effective amountalone to the surface of a plant. Such symptoms illustratively includenecrosis, leafburn, desiccation, wilting and the like as visibleevidence of herbicidal effectiveness.

As used herein, the term “long term control” means a significantinhibition of regrowth which is achieved through the use of aherbicidally effective amount of glyphosate (or glyphosate salt or amixture thereof) on a plant to be killed or controlled.

The formulation of the present invention contains at least onewater-soluble salt of glyphosate or a mixture of such salts. Severalprocesses for the preparation of glyphosate and its water soluble saltsare disclosed in the patent and chemical literature, e.g., U.S. Pat.Nos. 3,977,860 and 4,486,358. Illustrative suitable water-soluble saltsof glyphosate useful in the present invention are disclosed in U.S. Pat.No. 4,405,531. The isopropylamine salt of glyphosate is most preferredin the formulation, preparation of the formulation and use of thepresent invention.

If desired, one or more of ammonium sulfate or potassium sulfate or anyother compatible active or compatible nonactive ingredient may beemployed as an additional ingredient(s) in a process for preparing aformulation of the present invention, in its preparation and its use.

If ammonium sulfate is used during the formulation process, theformulation is normally filtered (or optional equivalent means) toremove any insoluble particulate materials which may be present in somecommercial grades of ammonium sulfate.

The concentrates and solutions of the invention may contain optionaladditional components, for example anti-freeze agents such as ethyleneglycol and propylene glycol.

Other examples are dyes, thickening agents, anti-foam agents, forinstance silicone-based anti-foam agents, and surfactants, for instancenon-ionic or cationic surfactants.

Additional illustrative suitable nonionic surfactants are recited inU.S. Pat. No. 4,405,531 supra. Other suitable nonionic surfactants willbe known to those skilled in the art.

Other surfactants which may be employed include alkylamine oxides, alkylglucosides, ethoxylated or propoxylated quaternary amines anddialkylacetylene surfactants.

Particularly preferred, although optional, is an ethoxylated tallowamine surfactant having a degree of ethoxylation in the range from about15 to about 18, mixtures thereof and the like. One such surfactant isEntry II, sold by Monsanto Company, St. Louis, Mo. USA.

The amount of surfactant optionally employed is typically in the rangefrom about 0 to about 2 percent by weight of a ready to use formulationof a spray solution formed by dilution with water of a concentrateformulation of this invention.

The concentrates and ready to use solutions of this invention may alsobe mixed with other water-soluble herbicides, for example but notlimited to, salts of 2,4-dichlorophenoxyacetic acid, dicamba or4-chloro-2-methylphenoxyacetic acid, or with finely-dividedwater-insoluble herbicides, for example but not limited to triazines,substituted ureas, sulfonylureas diphenyl ethers, dinitroanilines,pyridines and the like.

While Roundup® herbicide is the preferred source of a glyphosate watersoluble salt, other suitable formulations providing a water solubleglyphosate salt or glyphosate acid may be employed if desired.

Alternatively, the water soluble glyphosate salt or an aqueous solutionthereof may be prepared and then added directly as one of the processpreparation steps.

Some compositions of the invention were prepared by stirring about a 62percent by weight aqueous solution of the mono-isopropylamine salt ofglyphosate at about room temperature with the desired amount of fattyacid as a potassium salt and optionally, with a saturated solution ofammonium sulfate.

The formulations of the present invention may be conveniently preparedby mixing the desired ingredients together as in a blender or in anysuitable container of device producing the needed amount of agitationresulting in mixed ingredients.

Formulation examples were generally prepared by the following process:

(1) adding all or a portion of the desired amount of initial water in afirst container,

(2) adding a portion of water and potassium hydroxide to the desiredamount of fatty acid in a separate container to form a premix,

(3) adding the fatty acid containing the potassium hydroxide in thepremix from the separate container to the first container containing theinitial water,

4) adding a water soluble salt of N-phosphonomethylglycine alone withsurfactant to the first container to form a desired final non pHadjusted mixture/solution,

5) adjusting the mixture/solution to a final desired pH by addingappropriate amounts of a concentrated potassium hydroxide solution andthereafter if desired,

6) admixing any remaining water and optional ingredients such as ananti-microbial for example Proxel® GXL (CAS 2634-33-5), sorbic acid,Legend MK, mixtures thereof and the like.

The conversion of a fatty acid such as pelargonic acid to salt such as apotassium salt is the step requiring most scrutiny of the process ofthis invention.

Pelargonic acid is a thin, clear oil at room temperature which sits onthe surface of water when added. With mild agitation, the conversiontime to form the salt of the fatty acid is slow. Extreme agitation andlong batch stirring time are generally necessary to make the conversioncomplete which is desired.

In laboratory test batches, preparation of formulations of thisinvention was generally done by making the fatty acid salt in a separatesmaller premix vessel using a beaker and vigorous agitation. This premixwas then added to the already mixed ingredients in a larger firstcontainer.

As used herein the term “vigorous agitation” includes stirring or mixingby any mechanical or equivalent means to produce a well mixedcomposition providing thorough blending.

The process of preparing a formulation of this invention may be done attemperatures in the range from about 10° C. to about 100° C. andpreferably from about 20° C. to about 40° C.

As another optional ingredient, an anti-foam agent may be included.Various suitable anti-foam agents include SAG 47 which is preferred asan anti-foam agent and Silicone Anti Foam® 30 IND.

The amount of anti-foam agent optionally employed is that which issufficient to control and reduce an amount of foam which may be formedduring the process of preparation of the formulation of this inventionto a desired satisfactory level from a user's viewpoint. Generally theconcentration of anti-foam agent is in the range from about 0.001% byweight of the total ingredients to about 0.1% although greater or lesseramounts of optional anti-foam agent may be employed.

Alternatively, a premix of about 1 part by weight Roundup® herbicide,about 2 parts water and potassium hydroxide as a 20 percent by weightsolution was used to form a premix. Pelargonic acid was blended in thispremix but thereafter separated easily. The benefit of this(alternative) process of preparation was that the premix went into thebatch water with only mild agitation. Care must be given to preventpossible heat residue in the premix beaker.

The most preferred previously described process requires some agitation.It may be likely that the addition of the fatty acid at the suction sideof a flow through homogenizer Tekmar for example, into the potassiumhydroxide composition would be sufficient to produce the desired amountof agitation.

In a preferred process for preparing formulations of this invention, thevessel wherein the formulation will be 50 gallons or more is initiallycharged with about 25% of the total desired water. Gentle agitation orrecirculation is begun during and after this initial water addition. Abase providing hydroxide in water is added as is optionally anethoxylated tallowamine surfactant such as Entry II® Surfactant, sold byMonsanto Company, St. Louis, Mo. USA.

Agitation is increased and the added fatty acid is allowed to react.When the reaction is considered complete, the fatty acid appearshomogeneous and not aggregated at the surface of the resultingcomposition. About half of the remaining desired water is added as aredesired amounts of the isopropylamine salt of glyphosate, and optionallyProxel and Sag 47 with time allowed for adequate mixing. Thereafterremaining desired water is added and the pH is adjusted using potassiumhydroxide.

Ready to use formulations having C₉ or C₁₀ fatty acids in the range fromabout 0.5 to about 1% by weight of the total spray weight were the mosteffective formulations from a herbicidal efficacy viewpoint withmixtures thereof providing similar efficacy.

The formulations of the present invention can be readily used asprepared or further diluted in water by a user in a spray containerprior to use, although those of skill in the art will recognize that thedilution will have a practical dilution limit set by efficacy.

Suitable herbicidally efficacious application rates of glyphosate willvary depending on plant species, weather, climate and geography. Thespray volume is in the range from about 10 to about 1000 gallons peracre (gpa) preferably from about 50 to about 250 gpa. U.S. Pat. No.3,799,758 provides illustrative application rates of glyphosate on anacid equivalent basis.

The following examples are presented to illustrate the present inventionas well as some of the various embodiments of the invention. Theseexamples are presented as being illustrative of the novel formulationsand are not intended to be a limitation of the scope thereof. Ratherthese examples are intended to teach by illustration and provide what isbelieved to be a useful and readily understood description of proceduresto make and use the invention.

In the examples, all parts, percentages and properties are by weightunless otherwise indicated. In some examples, comparative formulationsillustrative of the prior art were made and compared to compositions ofthis invention.

EXAMPLES General Methods

Tall fescue, common bermuda, common dandelion, sweet clover and largecrabgrass were grown from seed in 4 inch square pots containing amixture of soil and commercial soil conditioners. After planting, thesoil was kept moist and seedlings emerged in 5-8 days. Approximately 2weeks after emergence, plants were mowed to a uniform height of 6 cm.Height was maintained at 6 cm with 3 mowings per week for fescue,bermuda and crabgrass and with 1 mowing per week for dandelion andclover. Unless otherwise noted, all species except crabgrass were about8 weeks old at the time of treatment. Crabgrass was 4-5 weeks old.Treatments were applied with a Devilbiss atomizer using compressed air.Chemicals were formulated as described for individual tests. For quicksymptom development (1-3 DAT), evaluations were made on a 0-3 scalewhere

0=no effect

1=injury noticeable compared to untreated control

2=injury obvious

3=injury dramatic

Percent control ratings at later time periods were made on a 0-100 scalewhere 0=no effect and 100 is complete death. Results are the average of2 replications.

Example 1

Combinations of C₈-C₁₂ saturated fatty acids as their potassium saltwith Gy glyphosate and an ethoxylated tallow amine surfactant having adegree of ethoxylation of about 15 to 18 were prepared.

Eight formulations containing either 0.5% or 1% C₈, C₉, C₁₀ or C₁₂saturated fatty acids in 0.96% glyphosate-IPA and 0.36% ethoxylatedtallow amine surfactant were applied respectively at 225, 112 or 56gallons per acre to 8 week old fescue and bermuda, 5 week old dandelionand sweet clover and 4 week old crabgrass. Visual observations ofburndown were made 1 DAT (Day After Treatment) on 0-3 scale and at 26DAT on 0-100 scale. Results are in Table 1.

TABLE 1 Weed control with combinations of fatty acids, glyphosate andethoxylated tallow amine surfactant. Fescue Bermuda Dandelion CloverCrabgrass Fatty acid GPA 1* 26* 1 26 1 26 1 26 1 26 None Prior 225  0**  98*** 0 98 0 100 0 70 0 98 None Art 112 0 95 0 95 0 95 0 40 0 98 None56 0 80 0 70 0 98 0 30 0 95 1% C₁₂ 225 0 98 0 98 0 98 2 60 2 99 1% C₁₂112 0 98 0 95 0 100 2 30 2 98 1% C₁₂ 56 0 85 0 70 0 95 0 30 1 98 0.5%C₁₂ 225 0 99 0 98 0 100 2 80 2 100 0.5% C₁₂ 112 0 95 0 90 0 98 1 30 2 990.5% C₁₂ 56 0 80 0 60 0 95 0 20 1 95 1% C₁₀ 225 2 98 1 95 2 100 3 80 398 1% C₁₀ 112 1 98 0 85 0 100 2 50 2 99 1% C₁₀ 56 0 90 0 50 0 75 2 30 195 0.5% C₁₀ 225 2 100  1 95 2 100 2 60 3 98 0.5% C₁₀ 112 1 95 0 90 0 1002 30 2 98 0.5% C₁₀ 56 0 90 0 70 0 95 1 30 1 95 1% C₉ 225 2 98 2 95 2 1003 70 3 98 1% C₉ 112 2 95 1 90 1 98 2 50 3 99 1% C₉ 56 1 80 0 60 0 95 230 1 95 0.5% C₉ 225 2 99 1 95 1 100 2 60 2 98 0.5% C₉ 112 1 95 0 90 0100 1 50 1 95 0.5% C₉ 56 0 80 0 60 0 85 0 20 1 95 1% C₈ 225 2 99 2 95 1100 2 60 3 98 1% C₈ 112 1 95 0 90 0 95 1 30 2 99 1% C₈ 56 0 80 0 50 0 901 20 0 98 0.5% C₈ 225 1 99 1 95 0 100 2 70 2 99 0.5% C₈ 112 1 95 0 90 0100 2 50 1 98 0.5% C₈ 56 0 70 0 50 0 95 0 30 0 98 *Days after treatment**Rated on 0-3 scale ***Rated on 0-100 scale

Example 2

Efficacy of C₉ and C₁₀ saturated fatty acids as the potassium salt aloneand in mixtures in combinations with glyphosate.

Eight week old tall fescue and bermuda, 4 week old crabgrass and 2 weekold yellow nutsedge were sprayed with C₉ and C₁₀ saturated fatty acidsat 0.5 and 1% w/v alone and in mixtures at volumes of 56, 112 and 225gal/A. Yellow nutsedge had not been mowed prior to spraying. Visualobservations of burndown were made on a 0-3 scale 1 DAT and percentcontrol was evaluated on a 0-100 scale 29 DAT. Results are in Table 2.

In Table 2 following C₉ and C₁₀ fatty acids and mixtures of both givesignificant enhancement of final control of yellow nutsedge byglyphosate, as indicated. Mixtures appear more potent in this regardthan either C₉ or C₁₀ fatty acid on its own. The fatty acids withoutglyphosate have zero effect on yellow nutsedge. Yellow nutsedge is amajor problem weed and one that is typically difficult to control withglyphosate-based products.

TABLE 2 Weed control with combinations of glyphosate with C₉ and C₁₀saturated fatty acids. Fescue Bermuda Crabgrass Y. nutsedge GlyphosateC₉ C₁₀ GPA 1* 29* 1 29 1 29 1 29 .74% ae Prior 0 0 225 0 100 0 95 0 1000 50 .74% ae art 0 0 112 0 98 1 98 0 100 0 70 .74% ae 0 0 56 0 95 1 90 0100 0 30 .74% ae    1% 0 225 3 98 3 95 3 95 0 85 .74% ae    1% 0 112 295 2 85 2 95 0 70 .74% ae    1% 0 56 1 90 1 70 2 90 0 40 .74% ae 0    1%225 3 95 2 95 3 98 0 70 .74% ae 0    1% 112 2 95 1 85 3 98 0 80 .74% ae0    1% 56 1 95 0 60 1 95 0 40 .74% ae   .5%   .5% 225 3 90 2 95 3 98 080 .74% ae   .5%   .5% 112 2 95 2 90 3 95 0 70 .74% ae   .5%   .5% 56 190 0 70 1 85 0 70 0 (Prior art)    1% 0 225 0 0 0 0 1 0 0 0 0 (Priorart)    1% 0 112 0 0 0 0 0 0 0 0 0 (Prior art)    1% 0 56 0 0 0 0 0 0 00 0 (Prior art) 0    1% 225 0 0 2 0 2 0 0 0 0 (Prior art) 0    1% 112 00 1 0 2 0 0 0 0 (Prior art) 0    1% 56 0 0 0 0 0 0 0 0 0 (Prior art)  .5%   .5% 225 2 0 2 0 3 0 0 0 0 (Prior art)   .5%   .5% 112 2 0 2 0 10 0 0 0 (Prior art)   .5%   .5% 56 1 0 1 0 0 0 0 0 .74% ae .25% .25% 2252 95 2 98 3 100 0 90 .74% ae .25% .25% 112 2 98 2 95 1 100 0 90 .74% ae.25% .25% 56 1 95 1 80 0 98 0 80 *Days after treatment ae is glyphosateacid equivalent

Example 3

Effect of C₉ and C₁₀ saturated fatty acids as its potassium salt onglyphosate.

Formulations containing 0.96% IPA-glyphosate (0.74% ae) and 0.4%ethoxylated tallow amine surfactant having a degree of ethoxylation of15 to 18 were prepared as shown in Table 3a. In addition a concentratedformulation containing 16.5% IPA-glyphosate, 6.15% ethoxylated tallowamine surfactant having a degree of ethoxylation of 15 to 18 and 4.1% C₉4.1% C₁₀ fatty acid was diluted and sprayed at the same finalconcentration of active. Treatments were applied at 56 and 112 gal/A.Visual observations of injury were recorded 1, 3 and 25 days aftertreatment. Results are shown in Tables 3a and 3b.

Example 4

Use of C₉ saturated fatty acid for enhanced burndown with Roundup® LLGready-to-use herbicide.

Results of treatments of Roundup® LLG ready-to-use herbicide alone andin mixture with C₉ saturated fatty acid at 0.5% and at 1.0% of the spraysolution are shown in Table 4.

Example 5

The effect of pH adjustment on performance of a mixture of Roundup® LLGready-to-use herbicide containing 1% C₉ saturated fatty acid is shown inTable 5.

TABLE 3a Glyphosate combined with saturated fatty acids applied at 56gal/Acre. Fescue Clover Dandelion Bermuda Crabgrass C₉ C₁₀ 1* 3* 25* 1 325 1 3 25 1* 3* 25* 1 3 25 0 0 (Prior art) 0 0 85 0 1 50 0 0 70 0 0 60 01 85 .5% 0 0 1 80 2 2 50 0 0 70 0 0 60 0 1 90 1% 0 0 1 60 2 2 40 0 0 300 0 50 0 1 90 0 .5% 0 1 70 2 2 30 0 0 80 0 0 50 1 2 80 .5% .5% 0 1 60 22 30 0 0 30 0 1 50 1 2 70 .5%** .5%** 0 2 80 2 2 30 0 0 50 0 0 40 0 1 70*Days after treatment **Diluted from concentrate

TABLE 3b Glyphosate combined with saturated fatty acids applied at 112gal/Acre. Fescue Clover Dandelion Bermuda Crabgrass C₉ C₁₀ 1* 3* 25* 1 325 1 3 25 1* 3* 25* 1 3 25 0 0 (Prior art) 0 0 95 1 2 20 0 0 90 0 0 80 01 95 .5% 0 1 1 98 2 2 20 0 0 80 0 0 80 1 2 95 1% 0 1 1 98 2 2 20 0 0 800 0 80 1 2 98 0 .5% 1 2 98 2 2 30 0 1 85 0 1 85 1 2 98 .5% .5% 1 2 99 12 40 0 1 60 0 1 70 1 2 98 .5%** .5%** 1 2 98 2 2 30 0 0 40 0 0 80 1 2 90*Days after treatment **Diluted from concentrate

TABLE 4 Effect of C₉ fatty acid on performance of commercially availableRoundup RTU ® herbicide applied at 56, 112 or 225 gal/Acre. FescueBermuda Dandelion Clover Crabgrass Additive GPA 1* 20* 1 20 1 20 1 20 120 None Prior 56  0**   80*** 0 85 0 70 0 60 0 90 None art 112 0 95 0 980 100 1 90 0 98 None 225 0 99 0 98 0 100 1 95 0 100 0.5% C₉ 56 0 90 0 800 80 2 50 0 95 0.5% C₉ 112 0 98 0 90 0 100 2 85 1 95 0.5% C₉ 225 1 99 098 0 100 2 85 1 100 1% C₉ 56 0 60 0 60 0 99 2 60 1 90 1% C₉ 112 0 90 095 1 98 2 85 2 95 1% C₉ 225 1 95 0 95 1 98 2 95 3 99 *Days aftertreatment **Rated on a 0-3 scale ***Rated on a 0-100 scale

TABLE 5 Effect of pH on activity of glyphosate with 1% C₉ fatty acid.Fescue Clover Dandelion Bermuda Crabgrass Treatment GPA 1* 3* 28* 1 3 281 3 28 1* 3* 28* 1 3 28 Roundup RTU 56 0 0 0 0 1 0 0 0 60 0 0 10 0 0 95112 0 0 20 0 1 0 0 0 100 0 0 70 0 0 95 168 0 0 20 1 1 0 0 0 99 0 0 70 00 95 225 0 0 50 1 2 60 0 0 96 0 1 90 1 1 95 +FA** pH 6.4 56 0 1 10 2 2 00 0 50 0 0 10 0 1 90 112 0 2 60 2 3 90 0 1 70 0 1 60 1 2 98 168 1 2 70 33 95 0 1 40 0 2 60 1 3 98 225 1 3 90 3 3 10 1 2 100 0 2 90 1 3 98 +FA**pH 6.75 56 0 1 10 2 2 30 0 0 50 0 0 10 0 0 80 112 0 2 10 2 3 70 0 0 1000 1 50 1 2 95 168 0 2 30 2 3 90 0 1 100 0 1 50 1 2 95 225 0 3 50 3 3 300 1 30 0 1 50 1 3 95 +FA** pH 7.25 56 0 0 0 2 2 0 0 0 50 0 0 20 0 0 80112 0 0 0 2 2 10 0 0 50 0 1 20 1 2 99 168 0 1 20 2 3 80 0 1 100 0 1 90 12 98 225 0 2 10 2 3 90 0 1 50 0 2 90 1 3 98 +FA** pH 7.71 56 0 0 0 2 250 0 1 50 0 0 10 0 0 80 112 0 1 10 2 3 80 0 1 100 0 1 10 0 1 95 168 0 120 2 3 90 0 1 100 0 1 10 0 2 95 225 0 1 50 2 3 70 0 1 100 0 1 50 0 2 95*Days after treatment **Roundup RTU + 1% C₉ fatty acid

Although this invention has been described with respect to specificembodiments, the details hereof are not to be construed as limitations,for it will be apparent that various equivalents, changes andmodifications may be resorted to without departing from the spirit andscope of this invention and it is understood that such equivalentembodiments are intended to be included within the scope of thisinvention.

What is claimed is:
 1. An agriculturally acceptable herbicidal aqueouscomposition providing initial visible symptoms of contact of a fattyacid or fatty acid salt component thereof and longer term herbicidalkill or control by N-phosphonomethylglycine or anN-phosphonomethylglycine salt component thereof, comprising: a)N-phosphonomethylglycine or one or more agriculturally acceptable watersoluble salts thereof or mixtures thereof or a compound whichmetabolizes thereto; and b) a C₈ to C₁₂ saturated or unsaturated,straight or branched chain fatty acid or agriculturally acceptable saltthereof or mixture of said C₈ to C₁₂ fatty acids and salt(s) thereof ormixture of salts of said C₈ to C₁₂ fatty acid(s) said composition havinga pH in the range from about 6.4 to about 7.25.
 2. The composition ofclaim 1 wherein the ratio by weight of component a) to component b) isin the range of about 1:10 to about 10:1.
 3. The composition of claim 1wherein the ratio by weight of component a) to component b) is in therange from about 1:5 to about 5:1.
 4. The composition of claim 1 whereinthe ratio by weight of component a) to component b) is in the range fromabout 1:3 to about 3:1.
 5. The composition of claim 1 wherein saidagriculturally acceptable water soluble salt of N-phosphonomethylglycineis the isopropylamine salt of N-phosphonomethylglycine.
 6. Thecomposition of claim 1, wherein said agriculturally acceptable watersoluble salt of N-phosphonomethylglycine is the trimethylsulfonium saltof N-phosphonomethylglycine.
 7. The composition of claim 1, wherein saidfatty acid is capric acid or pelargonic acid or a mixture thereof andsaid fatty acid salt is the potassium salt or salts of said fatty acid.8. The composition of claim 1, wherein the pH of the composition is inthe range from about 6.8 to about 7.0.
 9. The composition of claim 1,further comprising a surfactant.
 10. The composition of claim 9, whereinsaid surfactant comprises an ethoxylated tallow amine.
 11. Thecomposition of claim 1, wherein said fatty acid(s) and salt(s) thereofare present in a total fatty acid equivalent concentration of about 0.5%to about 1.0% by weight.
 12. The composition of claim 9, furthercomprising an antifoam agent.
 13. A method of killing or controllingplants, comprising applying to said plants a herbicidally effectiveamount of a composition according to any one of claim 2-12.
 14. Aprocess for preparing a composition of claim 1 comprising (i) adding towater in any order a) N-phosphonomethylglycine or an agriculturallyacceptable water soluble salt thereof or mixtures thereof or a compoundwhich metabolizes thereto and b) at least one C₈ to C₁₂ saturated orunsaturated, straight or branched chain fatty acid or an agriculturallyacceptable salt(s) thereof or mixtures thereof, and (ii) adding a baseto adjust the pH to within the range from about 6.4 to about 7.25. 15.The process of claim 14 wherein said pH is adjusted to within the rangefrom about 6.8 to about 7.0.
 16. The process of claim 14 wherein saidbase is a hydroxide or an amine.
 17. The process of claim 14 whereinsaid base is an alkali metal or alkaline earth metal hydroxide.
 18. Theprocess of claim 14 wherein said base comprises potassium or sodiumhydroxide.
 19. The process of claim 14 wherein said base comprisespotassium hydroxide.
 20. A method of killing or controlling plantscomprising applying to said plants a herbicidally effective amount of anaqueous composition providing initial visible symptoms of contact of afatty acid or fatty acid;. salt component thereof and longer termherbicidal kill of control by N-phosphonomethylglycine or anN-phosphonomethylglycine salt component thereof, wherein the compositioncomprises N-phosphonomethylglycine or one or more agriculturallyacceptable water soluble salts thereof or mixtures thereof or a compoundwhich metabolized thereto and a C₈ to C₁₂ saturated or unsaturated,straight or branched chain fatty acid or agriculturally acceptable saltthereof or mixture of fatty acids and salt(s) thereof or mixture ofsalts of fatty acid(s). said composition having a pH in the range fromabout 6.4 to about 7.25.
 21. A process of preparing a agriculturallyacceptable herbicidal aqueous composition providing initial visiblesymptoms of contact of a fatty acid or fatty acid salt component thereofand longer term herbicidal kill or control by N-phosphonomethylglycineor an N-phosphonomethylglycine salt component thereof comprising: (i)adding a portion of the desired amount of water in a first container;(ii) adding water and potassium hydroxide to the desired amount of fattyacid in a separate container from the first container to forth a premix,wherein said fatty acid is a C₈ to C₁₂ saturated or unsaturated,straight or branched chain fatty acid or agriculturally acceptable saltthereof or mixture of said C₈ to C₁₂ fatty acids mind salt(s) thereof ormixture of salts of said C₈ to C₁₂ fatty acid(s), (iii) adding saidpremix to the water in said first container to form a diluted premix;(iv) adding N-phosphonomethylglycine or a water-soluble salt ofN-phosphonomethylglycine or mixtures thereof to the diluted premix toform a non-adjusted mixture; and (v) adjusting the pH of saidnon-adjusted mixture to a final pH of 6.4 to 7.25 by adding anappropriate amount of a potassium hydroxide solution.
 22. The process ofclaim 21 which comprises the additional step of admixing any remainingwater and optional ingredients.